Resource Description Framework (RDF) is a collection of specifications originally designed as a meta-data model. The RDF meta-data model is based on an idea of making statements about resources in the form of subject-predicate-object expressions (e.g., triplets, triples, or RDF triplets). Typically, a subject denotes a resource, and a predicate denotes traits or aspects of the resource and expresses a relationship between the subject and an object.
A triplestore is a purpose-built database for the storage and retrieval of RDF meta-data. A triple store may be populated with data from a variety of structured and unstructured data sources. These may include, for instance, PDF documents, word processing documents, relational database data, XML feeds, and so on. In conventional techniques, a parser is often manually created for each data source to read the data and populate the database.
The application programming interface (API) for adding data to a triplestore varies from vendor to vendor. In a complex project where multiple, disparate data sources exist, each data source parser is typically matched to the underlying triplestorage API. However, if the triplestore vendor changes, each parser has to be updated to use the new API. This becomes problematic if many parsers are involved.